128564789 has 2 divisors, whose sum is σ = 128564790. Its totient is φ = 128564788.

The previous prime is 128564749. The next prime is 128564791. The reversal of 128564789 is 987465821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 111999889 + 16564900 = 10583^2 + 4070^2 .

It is a cyclic number.

It is not a de Polignac number, because 128564789 - 2¹² = 128560693 is a prime.

It is a super-2 number, since 2×128564789² = 33057809941229042, which contains 22 as substring.

Together with 128564791, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128564749) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64282394 + 64282395.

It is an arithmetic number, because the mean of its divisors is an integer number (64282395).

Almost surely, 2^128564789 is an apocalyptic number.

It is an amenable number.

128564789 is a deficient number, since it is larger than the sum of its proper divisors (1).

128564789 is an equidigital number, since it uses as much as digits as its factorization.

128564789 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 967680, while the sum is 50.

The square root of 128564789 is about 11338.6414089167. The cubic root of 128564789 is about 504.7085715191.

The spelling of 128564789 in words is "one hundred twenty-eight million, five hundred sixty-four thousand, seven hundred eighty-nine".